trotmaf



(No Model.)

Z. U. TROTMAN'.

LOOK.

No. 591,901. Patented Oct. 19,1897.

WITNESSES I IJV'VEKTOR QW-QL JAM Attorney UNITE STATES PATENT OFFICE.

ZINA U. TROTMAN, OF TRAVERSE CITY, MICHIGAN.

LOCK.

SPECIFICATION forming part of Letters Patent No. 591,901, dated October 19, 1897.

Application filed November 20, 1896. Serial No. 612,861. (1T 0 model.)

To aZZ whom it may concern.-

Be it known that I, ZINA U. TROTMAN, a citizen of the United States, residing at Traverse City, in the county of Grand Traverse and State of Michigan, have invented certain new and useful Improvements in Locks; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make anduse the same.

This invention relates to improvements in looks and keys; and it consists of certain novel constructions, combinations, and arrangements of parts, all of which will be hereinafter more particularly set forth and claimed.

In the accompanying drawings, forming part of this specification, Figure 1 represents a rear elevation of alock constructed according'to my invention. Fig. 2 represents an enlarged detail perspective view of the rear portion of the front plate of the lock surrounding the keyhole. Fig. 3 represents an enlarged detail perspective view of my improved key, and Fig. 4 represents a central vertical section through the same.

A in the drawings represents the lock, B the flange surrounding the keyhole of the same, and O myimproved key. The said look A may be of any desired construction provided with the usual bolt a and locking-tumbler a. The flange B is of a raised, flaring, crescent shape, and is applied about the upper or round portion of the keyhole a with its contracted ends 1) meeting at the juncture of said round portion of the slot with the straight portion of the same.

The key 0 comprises a bow c, a stem 0,

and a bit or web 0 The said stem 0 is provided with a longitudinal groove '0 in which is mounted a flat spring 0 This spring is secured at one end in the bottom of said groove by any suitable means. The opposite or free end of said spring normally lies at the bottom of said slot, and is secured to the inner end of the bit'or web 0 so as to normally draw said bit partially into the groove 0 The said bit 0 is out upon its outer end to properly fit the bolt a and tumbler a when inserted into the look. A ring a is provided about the stem 0 to prevent the free end of the spring cj from being pulled altogether out of the groove '0 when the key is being applied in position. The construction of the key is such that even 1 when the bit 0 is expanded into its operative position, sufficient of the same will project down into the groove 0 to "give it a firm hold upon the side wallsof the '0 has reached its uppermost position upon the broadest portion of the flange B, it has been expanded sufficiently to engage and raise the tumbler a and shoot the bolt a either one way or the other.

It will be observed that the length of the keyhole is just sufflcient to admit the key when the bit 0 is withdrawn into the groove 0 and also that if said bit remains in this position after being inserted in the lock and turned it would not reach either the tumbler a or the bolt a, and thus could not possibly operate the same. A rigid key having a bit of suflioient length to operate the tumbler and bolt of this look could not be inserted into the keyhole because of the size of the same, and, as above described, a rigid key small enough to be inserted into the keyhole would not operate the look. It

will thus be seen that the lock can only be operated by a key having an expansible bit out so as to be operated by the expanding flange surrounding the keyhole.

In the operation of my invention the bit 0 is expanded after being inserted into the keyhole and turned until it reaches the operating point, when it shoots the bolt. The continued rotation of said bit upon the flange B permits of its again being contracted into the groove 0 by means of the spring 0 and thus when the key reaches its first position it is ready to be withdrawn from the lock. The reverse action for shooting the bolt in the opposite direction simply requires the reverse rotation of the key. The tension of the spring in the shank, a spring having one end secured in the bottom of said slot, a bit secured to the free end of said spring, and aring applied about the shank to prevent any excessive outward movement of the spring, substantially as described.

2. The combination with a suitable lock having an eccentric flange arranged about its keyhole, of a key provided with an expansible bit adapted to engage said flange and be gradually expanded into the proper position for raising the tumbler and shooting the bolt, substantially as described.

3. The combination with a suitable lock having an eccentric flange arranged about its keyhole, of a key provided with a longitudinal slot, a spring having one end secured in said slot, and a bit mounted on the opposite end of said spring so as to normally lie in said groove but be capable of being positively and gradually withdrawn therefrom by engagement with the eccentric flange about the 30 key, substantially as described.

4:. The combination with a suitable lock having an expanding flange about its keyhole, of a key provided with a longitudinal slot, a spring having one of its ends rigidly 35 secured in the bottom of said slot, a bit mounted upon the free end of said spring and provided with inclined faces adapted to engage the flange about the keyhole to cause the expansion of said bit into the proper position to raise the tumbler and shoot the bolt, substantially as described.

5. The combination with a suitable lockhaving an expanding flange about its keyhole, of a key provided with a longitudinal slot, a spring having one end mounted in said slot, a bit mounted on the free end of said spring, and a ring mounted upon said key for preventing any excessive movement of said spring out of said slot, substantially so as described.

In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

ZINA U. TROTMAN.

Witnesses:

JOHN (J. DEVENDORF, S. M. BROWN. 

